Cytokine Genetic Polymorphism and the Risk of Systemic Lupus Erythematosus in a Sample of Iraqi Patients

Abstract

ABSTRACT
Background: Systemic lupus erythematosus is a multi-systemic autoimmune disorder,
with varying incidence and prevalence between populations. Cytokine imbalance has
been demonstrated in systemic lupus erythematosus patients. Therefore, genetic
polymorphisms in cytokine genes, which influence gene expression and cytokine
production, may have an important impact on systemic lupus erythematosus susceptibility
and severity.
Objective: To shed light on the association between cytokine genetic polymorphisms and
systemic lupus erythematosus in Iraqi patients, and to determine their impact on the risk of
this disease.
Methods: This study was conducted in Medical City Hospital during the period from June
2013 until the end of October 2014. Forty six systemic lupus erythematosus patients were
enrolled in this study; their age range was (18-45). Mean ±SD was (35.0±5.2) years and
they were compared with 44 healthy controls. About 5 ml of blood sample was obtained
from every systemic lupus erythematosus patient and control. The separated serum was
used for measurements of interleukin-2, interleukin-6, and cytokine genetic polymorphism.
Results: Interleukin-2 showed a significant decreased level in patients as compared to the
controls (P ≤ 0.001). In contrast, Interleukin-6 was significantly increased in patients as
compared to the controls. Genetic polymorphisms of two cytokine genes (interleukin-2 and
interleukin-6) at 4 positions (IL2-330, IL2+160, IL6-174 and IL6+565,) were determined in
patients and the controls.
Conclusions: It can be concluded that interlukine-2 level was significantly higher in the
control group as compared with the patients group. Serum interleukin-6 was increased in
patients as compared to the control group, so the decrease in IL-6 concentration might
help to prevent systemic lupus erythematosus disease.